[Asterisk-Users] Slightly [OT] Asterisk Backends

[Andrew Niemantsverdriet]

I use Askerisk in my home as my home phone system. I use to make long
distance calls because of the cost savings that I can get. I also
share my phone system with my neighbor via a wireless link so that he
can also use * to make long distance calls at a savings. He also uses
that as a second emergency phone line.  So for all of that I just have
an internet connection and 1 X100P that goes to my phone line. That is
as big of scale as I have seen.

My question is how to the bigger companys do it? Do they have just a
bunch of phone lines that plug into their computer? What kind of cards
do they use, I know that they don't use 100's of X100P cards so what
are they? And lastly how can companys make money on such ventures?
Judging by the price of my single phone line it would be hard to have
much of a margin even with a T1.

Like I said in the subject off topic but I have wondered how my voip
provider makes any money.